Apparatus for strapping loaded pallets



April 1968 o. P. STERNER 3,376,807

APPARATUS FOR STRAPPING LOADED PALLETS Original Filed July 18, 1961 4 Sheets-Sheet l '55 %/Q 64 1 Q4 J06 9/ il S 9 .96 f 9g IHHHHH HHHUL April 9, 1968 o. P. STERNER 3,376,807

APPARATUS FOR STRAPPING LOADED PALLETS Original Filed July 18, 1961 4 Sheets-Sheet 2 0556 1 Sis W rmer/ April 9, 1968 o P. ST-ERNER APPARATUS FOR STRAPPING LOADED PALLETS RQQN 4 Sheets-Sheet Ofi p gzemez/ I allarw f5,

Original Filed July 18, 1961 April 9, 1968 o. p. STERNER 3,376,807

APPARATUS FOR STRA PPING LOADED PALLETS Original Filed July 18, 1961 4 Sheets-Sheet 4 United States Patent 3,376,807 APPARATUS FGR STRAPPING LOADED PALLETS Olle P. Sterner, Park Ridge, 111., assignor to Signode Corporation, a corporation of Delaware Continuation of application Ser. No. 124,984, July 18, 1961. This application June 13, 1966, Ser. No. 557,323 5 Claims. (Cl. 100-26) This application is a continuation of Ser. No. 124,984, filed July 18, 1961, and now abandoned.

The present invention relates to apparatus for strapping a loaded pallet, particularly to a strapping press assembly having a strap chute system that will provide a closed path for strapping to be tensioned and sealed about a load mounted on a pallet having either ope-n or closed bottoms.

Pallets that are used for holding material for storage or transportation as in a warehouse generally come in one of two forms. One type of pallet consisting of a rectangular plate mounted on four legs or two runners is generally referred to as an open-bottom pallet since the bottom of the pallet is accessible from at least two sides. The strap is disposed under the plate between the legs or runners. The second type consists of two vertically spaced plates that are separated by the legs interconnecting the corners of the two plates. This form of pallet will be referred to as a closed-bottom pallet since the space under the pallet platform is substantially enclosed. With such a pallet, the preferred way to strap a load to the pallet is to run the strap through the space or void formed between the plates and the legs interconnecting them.

Prior to this invention, the strapping of a loaded pallet was essentially a manual operation with the strap being wrapped around the load and then put into a strapping tool where the strap was tightened about the load, sealed into a tension resisting joint and then severed from the strap supply.

In the case of open-bottom pallets, a strap chute was located between the rollers of a conveyor and the strap looped around the load and then directed through the lower strap chute. This required at least two men and was a very costly and time consuming procedure. The strapping of a closed-bottom pallet presented the additional problem of providing a strap chute for guiding the strap through the void in the pallet between the two platforms, which chute would have to be removed before the strapped pallet could be moved from the strapping area. Various ways have been tried, such as threading one end of a strap through the pallet void or placing a portable strap chute section between the plates of the pallet. After the strap was tensioned about the pallet, the chute had to be manually withdrawn and moved away from the strapping station. This required storage space and was time consuming. Another limitation to these previous methods of strapping loaded pallets was that the tightness of the bundle was dependent on the tensioning device used to tension the strap before the ends were sealed.

In accordance with the present invention, there is provided a strapping apparatus that will automatically perform all the functions necessary to, wrap a metal band tightly around a loaded pallet. That is to say that the mechanism provided will, (1) function to compress the palleted load automatically, (2) provide a chute system for guiding a strap around either a closed-or open-bottom pallet, (3) direct a strap through the chute system, and (4) tension the strap about the pallet and untie the ends of the strap into a tension resisting joint.

To accomplish, this, the loaded pallets are located on a platform in the strapping press which is normally part of a roller conveyor system to facilitate easy handling of the loaded pallet. The loaded pallet is then compressed by a hydraulically operated platen to obtain a tight bundle so the load will not move or slide after it has been strapped. The strap is then directed through the strap chute system encircling the load to place the strap in a position to strap the load when the power strapping machine is operated to tension and seal the strap about the load.

The strapping of a load to an open-bottom pallet is accomplished by providing a lower guide chute bet-ween the rollers of the platform on which the pallet is located. This lower chute portion is fixed in place and interconnected with the side strap chutes to form a complete loop about the loaded pallet. This lower chute obviously need not be retractable since it does not present an obstruction to the removal of the pallet from the platform. The moving of the strap through the chute and the tensioning, sealing of the strap ends, and severing of the strap from the strap dispenser is done by a power operated machine provided for this purpose.

When a closed-bottom pallet is to be strapped, a bayonet type strap chute is interconnected between the side strap chutes. The bayonet chute is driven through the void in the pallet by a drive mechanism provided for this purpose. After the pallet has been strapped, the bayonet chute is retracted to permit removal of the strapped load. The chute system includes curved guide portions which when suitably positioned will guide the strap between the side chute sections and the bayonet chute.

- Suitable control devices are provided to insure that the various mechanisms of the strapping apparatus cannot be operated unless all the devices are in their proper positions. For example, the power strapper will not operate unless the bayonet strap chute is either in the fully extended or fully retracted position. Also, no additional biasing force will be supplied to the platen to compress the load'after the bayonet chute has been directed through the void in the pallet to prevent damage to the bayonet if the pallet should break under the pressure of the platen.

The structure by means of which the above-noted and other advantages of the invention are attained is fully described in the following specification, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a partial side view of a strapping station showing the apparatus in position to strap a closed-bottom pallet;

FIGURE 2 is a view in perspective of one end of the strapping apparatus showing from left to right: (I) the chute system in position to strap an open-bottom pallet, (2) the bayonet strap chute in an intermediate position, and (3) the bayonet chute in position to strap a closedbottom pallet;

FIGURE 3 is a cross-sectional view of the lower portion of the strapping apparatus with the bayonet strap chute being shown in the partially extended position;

- FIGURE 4 is a cross-sectional view of the bayonet chute;

FIGURE 5 is a plan view of the bayonet chute in the retracted position with parts broken away to show the support and drive therefor;

FIGURE 6 is a view taken along lines 66 of FIG URE 3;

FIGURE 7 is an enlarged side view of the front end of the bayonet chute;

FIGURE 8 is a composite cross-sectional view showing the position of various components of the lower strap chute and the bayonet chute when the strap is being withdrawn from the chute during the tensioning of the strap about the loaded pallet;

FIGURE 9 is a view taken along lines 99 of FIG- URE 3;

FIGURE 10 is a view taken along lines 1010 of FIGURE 3;

FIGURE 11 is a view in perspective of a strapped open-bottom pallet;

FIGURE 12 is a view, in perspective, of a strapped closed-bottom pallet; and

FIGURE 13 is a partial schematic view of a circuit diagram that illustrates the electrical interconnection between the overhead assembly, the strapping machine, and bayonet chute.

Referring now to the drawings, it is seen that the strapping press assembly 1 illustrated in FIGURE 1 includes a-platform 2 on which is located a loaded closedbottom pallet 3 to be strapped as shown in FIGURE 12. The platform is made up of two rows of rollers 4 supported on frame members 6 that are secured to a base support 7. This type of platform facilitates positioning of the pallet to the proper location in the strapping apparatus. When the pallet is properly positioned, an overhead assembly 8 including a platen (not shown) is moved downwardly to compress the load on the pallet into a tight bundle. The overhead assembly 8 is slidably supported relative to the vertical side portions 9, 11 to permit the strapping press to handle loads of different heights. The overhead assembly 8 is loaded in compression by supplying fluid under pressure to the top side of a piston rod assembly 12 located in a cylinder 13. There is a piston rod and cylinder assembly located on each side of the press. One end of the rod assembly 12 is secured to the base support 7 and the other end is connected to the overhead assembly 8.

Mounted within the overhead support assembly 8 are one or more power strapping machines 10. The number of strapping machines used will depend on the number of straps to be used for strapping the load to the pallet 3. The strapping machine directs the strap S through a chute system, to be described in detail hereinafter, extending completely around the loaded pallet. When the strap S returns to the strapping machine, it is tensioned about the pallet and held in the tensioned position until the ends of the strap are sealed to hold them in position. A suitable strap dispenser (not shown) is disposed adjacent each of the power strapping machines 10. Briefly, the strapping machine feeds strapping through the chute system to form a loose loop with portions of the strapping overlapped in juxtaposition with each other, reverses the feed suflicient to tighten the strapping about the loaded pallet, seals the strapping at the overlapped portions, and then cuts the strapping on the supply side of the strapping at the sealing zone. The details of the strapping machine and dispenser are not important to an understanding of the present invention. A strapping machine of'the type referred to is disclosed in United States Patent No. 2,915,003, issued to G. A. Crosby et al., and assigned to the assignee of the present invention.

The strapping machine 10 feeds the strap S through the chute system in the direction indicated by the arrow A in FIGURE 1. Essentially, the strap is directed through an upper chute portion (not shown) in the overhead assembly 8, down the left-hand vertically disposed strap chute 14, longitudinally across the bottom of the pallet or through the void of the pallet, depending upon the type of pallet being strapped, and then up to the rightnally spaced angle irons 15 and an L-shaped strap cover or gate 18. The strap gate 18 is loosely secured to the angle irons 15 by brackets 26 at longitudinally spaced intervals (see FIGURE 3). The strap gate and support block 17 form a channel 19 through which the strap is moved during the strapping operation. The L-shaped strap gate 18 is resiliently biased against a side support 21 by a number of longitudinally spaced spring assemblies 22. Each spring assembly 22 consists of a compression spring 23 located between a nut 24 and a bracket 26. The nut 24 is threaded on a bolt 27 which has a head 28 that engages angle iron 15. Thus, the L-shaped strap gate 18 is free to move outwardly against the springs 23 to permit the strap S to be withdrawn from the strap channel 19 when the strap is tensioned about the loaded pallet. The specific details of these portions of the strap chute are not critical and suitable modifications can be made where necessary to conform to the structural dehand vertical strap chute 16 to the upper chute and the strapping machine 10.

The upper strap chute and the upper portions of the vertical strap chutes are generally similar and serve as passageways for the strap irrespective of the type of pallet being strapped. The general configuration of these sections of the strap chute is illustrated in the lower half of FIGURE 8. It is to be noted that while the portion of FIGURE 8 referred to illustrates the lower strap chute, it was chosen since it illustrates the construction of the chute sections referred to in this paragraph. These strap chute sections include a longitudinally extending support block 17 to which are secured a plurality of longituditails of the chute supporting structure. The corner sections of the portion of the strap chute system interconnecting the upper chute section with the two vertical sections 14, 16 are open curved guide sections 30, 31 and thus are not provided with resiliently mounted strap gates of the type above described.

The lower horizontal portion of the strap chute system differs in accordance with the type of pallet being strapped. If an open-bottom pallet 32 is strapped (see FIGURE 11), a lower guide chute 33 is fixed in place between a pair of adjacent rollers 4 and below the upper surface of the platform 2 (see FIGURE 8). The construction of this lower guide chute 33 is shown in the bottom portion of FIGURE 8 and was described in detail in the preceding paragraph.

Disposed between the vertical strap chute section 14 and the lower strap chute 33 is a strap deflector assembly 34. This strap deflector 34 is shown in plan in FIG- URE 9, and a side view thereof, partially broken away, is illustrated in FIGURE 3. The deflector functions to direct the strap into the lower strap chute or the bayonet strap chute, depending on the type of pallet being strapped. The strap deflector is made up of two side plates 36, 37 to which are secured guide blocks 38, 39, respectively. These guide blocks 38, 39 form with guide block 41 a strap guide channel 42 that receives the strap from the vertical strap chute 14 and directs it into the strap channel 19 formed in the lower strap chute. The side plates 36, 37 are hinged to block 41 and are resiliently biased toward each other by spring assemblies 43, 44. As shown in FIGURE 9, the spring assembly located on the left side of the deflector consists of a spring 46 loaded in compression around stud 47 threaded through plate 36 into block 41 and plate 36. The bottoms of the blocks 38, 39 are tapered toward the center to facilitate removal of the strap from the deflector during the tensioning operation. Thus, it can be seen that the plates 36, 37 with their respective blocks 38, 39 can be moved away from each other to permit the strap to be withdrawn from the strap channel 42. The guide blocks 38, 39 of the strap deflector also define a chute curve 50 on their upper surface for directing the strap into a bayonet strap chute 51.

The path that the strap takes through the strap deflector assembly 34 is determined by the strap selector section 52 of the chute system. This portion of the chute system is shown in FIGURES 3 and 10 and is similar in construction to the lower guide chute shown in FIG- URE 8. The strap selector assembly consists of a chute gate 53 that is resiliently held in place relative to support column 14 by spring assembly 22 acting on plate 54 that is secured to gate 53. The spring assembly includes a bolt 28 that extends through angle iron support 56 which is connected at its other end to chute side plate 57. Side plate 57 is pivotally mounted relative to column 14 by pivot pin 58. Thus, it can be seen that the assembly made up of gate 53, plate 54, spring assembly 22, angle iron 56, and plate 57 is pivotally mounted relative to column 14.

The bottom of the chute channel is selector section 52 is defined by pivot plate 60 which extends through side plate 57 to the side of gate 53. The location of plate 60 relative to strap channel 52 or chute curve 50 of strap deflector 34 will determine the path the strap takes through the strap deflector. The positioning of strap selector 52 is determined by spring 61 and air cylinder 62 mounted on plate 63. The selector section 52 is normally maintained in position to direct strap into channel 42 by tension spring 62 which is connected at one end to anchor pin 64 secured to plate 63 and at its other end to pivot plate 60. The selector can be pivotedto direct strap into guide curve 50 by cylinder 62 which acts through rod 66 against angle iron 56 to pivot the strap selector about pivot pin 58.

Following through the strapping of an open-bottom pallet 32, it is seen that there only remains to describe that section of the strap chute system interconnecting the lower strap chute 33 to the upper portion of the vertically extending chute section 16 of the strapping press. This portion of the strap chute system is best illustrated in FIGURE 5 and in the foreground of FIGURE 2 and comprises a curved open section 70 and a curved closed section 71. The closed section is made in two pivotally mounted halves 72, 73. Each half includes a generally L-shaped vertically extending plate 74. Bolted to each of these plates 74 are guide blocks 76, 77 which define therebetween a strap channel 78 for the passage of strap. As seen in the middle of FIGURE 2, where this guide section 71 is shown in the open position, the outer blocks 76 extend only half-way down the L-plates 74 and the inner blocks 77 define a generally curved guide arrangement. The withdrawing of the strap from the channel 78 when the strap is to be tensioned about the loaded pallet is permitted by-resiliently mounting the strap guide assemblies 72, 73 into the channel forming position. To this end, each plate 74 is secured to a vertically extending angle iron 79 that is in turn secured to a pair of pivotally mounted, vertically spaced links 81, 82. These links 81, 82 are pivoted to two vertically spaced frame members 83, 84 (see FIGURE 2). The cooperating strap guide assemblies 72, 73 are resiliently maintained in the position shown in FIGURE 5 by tension springs 86: that are secured at one end to a bracket 87 and at their other end to a frame member 88. The guide rollers 89 secured to each of the pivot links and the switches 91, 92 positioned by the links 81 are not pertinent to the operation of the strapping press when strapping open-bottom pallets. Their functions will be described in detail hereinafter when discussing the strapping of closed-bottom pallets. It suffices to note at this time that with the switches 91, 92 in the position illustrated in FIGURE 5, the strapping machine 1 is free to operate to direct strap through the strap chute system, and the overhead support assembly 8 will operate to compress the loaded pallet and maintain same compressed during the strapping operation.

When a closed-bottom pallet 3 of the type shown in FIGURE 12 is to be strapped on the roller platform, a chute section must be provided to direct the strap through the void in the pallet. In accordance with the present invention, this is accomplished by providing an extendable and retractable bayonet-type strap chute 51. When the bayonet chute is fixed in position, it provides a passageway for the strap from one side of the chute system through the void in the pallet to the other side of the strap chute system. The bayonet chute 51 is shown in cross-section in the upper portion of FIGURE 8 and various other views of the bayonet are found in FIG- URES 3, 4, 5, 6, and 7. The bayonet strap chute 51 includes a bottom plate 93 on which is mounted a box section 94. The upper surface of the box section 94 forms the bottom wall of the strap channel 96. The other three sides of the strap channel 94 are formed by a pair of cooperating longitudinally extending T-shaped plates 97, 98 located on opposite sides of the box section 94. Secured to the T-plates 97, 98 arelongitudinally spaced brackets 99 that are loosely connected to the box section by double-headed retaining pins 101. The T-plate and bracket assemblies are resiliently maintained in the strap channel forming position and thus are capable of moving away from the box section 94 to release the strap when it is to be tensioned about the loaded pallet 3. This opening and closing movement of the bayonet 51 is permitted by resiliently biasing the T-plates into abutting relationship by compression springs 102 located at longitudinally spaced points along the length of the bayonet chute 51 (see FIGURE 4). The springs 102 are guided by projections 103, 104 extending toward each other from the bottom plate 93 and adjacent T-plate.

The lower front end portion 51a of the bayonet strap chute 51 is U-shaped (see FIGURES 6 and 7) and has secured to each leg of the U a roller 105. When the bayonet 51 is moved into the fully extended position, the end portion 51a is disposed between rollers 106, 107 of strap deflector assembly 34 and the rollers straddle plates 36, 37 (see FIGURE 3).

Secured to an intermediate portion of bayonet chute 51 is an open curved guide section 108. This guide section 108 replaces the cooperating guide sections 72, 73 to direct the strap from the bayonet channel 96 to the vertical strap section 16 when a closed-bottom pallet is being strapped (see FIGURE 2). Specifically, the angle iron bracket 120 locates between the rollers 80 when the bayonet is fully extended, in order to align the upper end of curve 108 with the vertical strap chute 16.

The bayonet strap chute 51 must be in a retracted position to permit a closed-bottom pallet to be placed on the platform 2 for strapping and must be movable longitudinally through the void in the pallet to provide a passageway for the strap. In the embodiments illustrated, the bayonet chute 51 is moved between the retracted and extended positions by power driven rollers 109, 110 that frictionally engage the bottom plate 93 of the bayonet chute. These rollers 109, 110 are rotated by a motor 111 which drives sprockets 112, 113 secured to the rollers 109, 110 by chains 114, 115 (see FIGURE 3). The motor 111 is reversible and thus will be rotated in one direction to move the bayonet chute across the platform 2 to provide a guideway for the strap, and after the strap is withdrawn from the bayonet chute, the motor will be rotated in the other direction to remove the bayonet chute from the closed-bottom pallet, the forward movement of bayonet chute 51 is dampened and the bayonet is held in place by a solenoid operated drag brake assembly 116. Brake assembly 116 includes a link 117 and brake arm 118 which is pivotally moved into engagement with bayonet bottom plate 93 by spring 119. Actuation of solenoid 121 moves brake arm 118 away from plate 93 to release the bayonet when the motor is reversed to retract the bayonet. Briefly, solenoid 121 is energized whenever power is applied to the motor 111. Thus, there is no drag brake applied while the motor is operating, but when the motor shuts off, the brake is applied to dampen the impact against curve 34 and to prevent reverse motion of the bayonet when the strap is pushed through the bayonet. In retracted position, the bayonet is prevented from premature forward motion due to vibration, etc., by the friction of the drag'brake.

As shown in FIGURES 3, 4, and 5, the bayonet chute is guided relative to the drive rollers 109, 110 in the vertical plane by rollers 122, 123 which engage the upper surface of the bayonet bottom plate 93. The bayonet chute is guided in a horizontal plane by rollers 124, 125. The horizontal and vertical guide rollers are rotatably supported by suitably positioned frame members.

It remains to note that a trip plate 127 is connected to the top of bayonet chute 51 at its rear end for tripping switch 128. Switch 128 functions to shut off motor 111 and to signal strapping machine 10 to direct strap through the chute system, when the bayonet chute is in the fully extended position. v

The methods of operation of the strapping apparatus for strapping openand closed-bottom pallets are as follows:

When strapping open-bottom pallets, the loaded pallet is placed On the platform 2 and the hydraulic rod and cylinder assembly 12, 13 is actuated to move the overhead assembly 8 and associated platen (not shown) into contact with the load to compress the load on the pallet. The strapping machine 10 is then actuated to feed strap through the chute system including an upper chute portion, open guide 30, vertical section 14, strap channel 42 in strap deflector 34, strap channel 19 in lower strap chute 33, open chute curve 70, channel 78 in closed curved section 71, vertical chute section 16, and guide 31 to the upper chute section and back into the strapping machine 16. The strap selector is positioned by spring 61 to direct the strap into channel 42. The strapping machine is then reversed to tighten the strapping about the loaded pallet, seal the strapping at the overlapped portions, and then cut the strap on the supply side of the strap at the sealing zone. During the tensioning operation, the resiliently supported chute covers are opened up to release the strap therefrom. When strapping closed-bottom pallets, the overhead assembly 8 is moved downwardly to compress the load in the same manner as when open-bottom pallets are strapped. The motor 111 is then actuated to move bayonet chute 51 through the void in the closed-bottom pallet located on platform 2. The end 51a of the bayonet chute is located between the rollers 106, 107 of the strap deflector assembly 34 to locate the bayonet chute properly in position. When the motor is operated, the solenoid drag brake 116 is energized to release the brake arm from the bottom of bayonet bottom plate 93. At the same time the air cylinder 62 is energized to move the strap selector assembly 52 into position to direct the strap from the vertical chute section 14 into the chute curve 50 of the strap deflector 34. The longitudinal movement of the bayonet chute 51 places the chute curved guide section 108 in position to direct the strap from the bayonet chute channel 96 into the vertical strap chute section 16. This positioning of the guide section 108 occurs when rollers 105 of bayonet end section 51a engage links 81 and move guide section 71 out of the way against the action of springs 86, as shown in FIG- URE 2. This movement of guide section 71 actuates switches 91, 92 to prevent further downward movement of overhead assembly 8 and prevents strapping machine 10 from operating. When the bayonet is fully extended, switch 128 is tripped by plate 127 to permit the strapping machine to operate. With the bayonet chute in the extended position, the overhead assembly stays in the position in which it was placed by the hydraulic assembly 11, 12 to prevent possible breaking of the bayonet chute by the imposition of an excessive force on the overhead assembly. With the bayonet in the extended position and the strap selector positioned to direct the strap to the bayonet strap channel through guide 50 of strap selector 34, the strapping machine is actuated to complete the strapping operation. Briefly, the strap is fed from the strapping machine 10 through an upper chute section, vertical section 14, strap selector 52, strap deflector guide 50, bayonet chute channel 96, curved guide 108, vertical section 16, and into the upper chute section and strap ping machine 10. The loop of strap is then tensioned and sealed in the manner previously indicated.

It will be appreciated that numerous modifications may be made without departing from the scope of the invention. For example, the particular configurations of the guide chutes can be altered to include a bayonet chute having a different strap gate arrangement. Also, the control mechanisms and the support system for the bayonet chute are intended to be merely representative of various arrangements that could be employed.

Furthermore, while the specification has been directed to apparatus for tying a load to a pallet, the application of the present invention is not limited to such a use. For example, the novel mechanisms disclosed herein can be used to tie one or more loads together by extending a ligature through openings formed in the loads being tied. Such loads may be located on the ground or on a conveyor platform instead of on a pallet.

Although two embodiments of the invention have been described in considerable detail, it should be understood that the modifications thereof were intended to be illustrative only rather than restrictive.

What is claimed is:

1. Apparatus disposed at a strapping station for strapping a load to a pallet having spaced support means including a platform and defining a horizontal opening extending between said spaced support means below said platform comprising means for compressing the load disposed on the pallet, a strap guiding means completely encircling the platform and said load including reciprocally mounted chute means positioned to extend through the opening in said pallet, said chute means having a passageway for strap therethrough defined by a resiliently mounted closure, means for extending the chute means through said'opening to guide the strap therethrough, means for directing a strap through said guide means completely around the load and through the opening defined by the pallet, mean for tensioning the strap about the load and pallet, means for sealing the strap into a tension resisting joint, and means for retracting the chute to permit the strapped loaded pallet to be removed from said strapping station.

2. Apparatus as set forth in claim 1 in which said retractable chute means defines a longitudinally extending enclosed chamber for guiding said strap through the opening in said pallet, said chamber being defined by a bottom support member and an enclosure assembly resiliently maintained in place to facilitate guiding of the strap through said chamber, but which permits removal of the strap therefrom when the strap is tensioned about the loaded pallet.

3. Apparatus as set forth in claim 1 in which resiliently mounted closure means are provided for enclosing the encircling strap guiding means throughout substantially its full length, whereby removal of the strap from the guide means when the strap is tensioned is facilitated, the enclosure means for said retractable chute consisting of a pair of oppositely disposed, resiliently mounted plate members which in conjunction with a rigid support member define a chamber wherein the strap is located during the strapping operation, said resilient means including a pair of tension springs disposed on opposite sides of said rigid support member.

4. A strapping apparatus for disposing a plurality of straps about a palleted load located on a conveyor, said pallet having spaced support means including a platform and defining a horizontal opening extending between said spaced support means below said platform, means for compressing the load on said pallet including a platen adapted to contact the upper part of said load, a plurality of transversely spaced strap guiding means, each of said guiding means completely encircling the platform and load thereon and including a lower strap guiding assembly disposed beneath the conveyor for guiding a strap below the pallet and a generally horizontal retractable guide assembly located above said conveyor and having a passageway for strap therethrough defined by a resiliently mounted closure which can be moved through said horizontal opening to form a guideway therethrough, means for moving said retractable chute through said opening to direct strap therethrough and thus guide the strap through the horizontal opening in the pallet rather than through the lower Strap guiding as emb y, means for directing strap around said loaded pallet, means for tensioning said strap, means for sealing said strap in a tension resisting joint, and means for retracting the retractable chute upon completion of the strapping operation, whereby a plurality of straps can be disposed about said load to secure same to the pallet.

5. A strapping apparatus for disposing a plurality of straps about a palleted load located on a conveyor, said pallet having spaced support means including a platform and defining a horizontal opening extending between said spaced support means below saidtplatform, means for compressing the load on said pallet including a reciprocably mounted platen adapted to contact the upper part of said load, strapping apparatus disposed on said platen, a plurality of transversely spaced fully enclosed strap guiding means, each of said guiding means completely encircling the platform and load thereon and including a guide chute in said platen and vertically disposed guide chutes extending downwardly from said platen and constructed and arranged to interconnect with the guide chute in said platen, a lower strap guiding assembly disposed beneath the conveyor for guiding a strap below the pallet and a generally horizontal retractable guide assembly located above said conveyor and having a passageway for strap therethrough which interconnects with said vertical guide chutes and which can be moved through said horizontal opening to form a guideway therethrough, said pasageway being defined by a resiliently mounted gate assembly which will permit the strap to be withdrawn therefrom when the strapping machines are operated, mean for moving said retractable chute through said opening to direct strap therethrough and thus guide the strap through the horizontal opening in the pallet rather than through the lower strap guiding assembly, means for tensioning said strap, means for sealing strap in a tension resisting joint, and means for retracting the retractable chute upon completion of the straping operation, whereby a plurality of straps can be disposed about said load to secure same to the pallet.

References Cited UNITED STATES PATENTS 2,215,121 9/1940 Harvey et al. 10026 X 2,632,381 3/1953 Buckland 10025 X 2,780,986 2/1957 Ritenour 10025 2,831,422 4/1958 Black et al. 10030 X 2,908,215 10/1959 Fawcett a- 10026 2,959,118 11/1960 Hager 10026 2,985,098 5/1961 Winkler 10025 3,052,178 9/1962 Hall 10025 3,213,781 10/1965 Collins et al. 10026 BILLY J. WILHITE, Primary Examiner. 

1. APPARATUS DISPOSED AT A STRAPPING STATION FOR STRAPPING A LOAD TO A PALLET HAVING SPACED SUPPORT MEANS INCLUDING A PLATFORM AND DEFINING A HORIZONTAL OPENING EXTENDING BETWEEN SAID SPACED SUPPORT MEANS BELOW SAID PLATFORM COMPRISING MEANS FOR COMPRESSING THE LOAD DISPOSED ON THE PALLET, A STRAP GUIDING MEANS COMPLETELY ENCIRCLING THE PLATFORM AND SAID LOAD INCLUDING RECIPROCALLY MOUNTED CHUTE MEANS POSITIONED TO EXTEND THROUGH THE OPENING IN SAID PALLET, SAID CHUTE MEANS HAVING A PASSAGEWAY FOR STRAP THERETHROUGH DEFINED BY A RESILIENTLY MOUNTED CLOSURE, MEANS FOR EXTENDING THE CHUTE MEANS THROUGH SAID OPENING TO GUIDE THE STRAP THERETHROUGH, MEANS FOR DIRECTING A STRAP THROUGH SAID GUIDE MEANS COMPLETELY AROUND THE LOAD AND THROUGH THE OPENING DEFINED BY THE PALLET, MEANS FOR TENSIONING THE STRAP ABOUT THE LOAD AND PALLET, MEANS FOR TENSIONING THE STRAP ABOUT THE LOAD AND JOINT, AND MEANS FOR RETRACTING THE CHUTE TO PERMIT THE STRAPPED LOADED PALLET TO BE REMOVED FROM SAID STRAPPING STATION. 